Many products are shipped and sold in containers which are not well suited to retain product freshness throughout the period during which the contents of the container are used or consumed. Pet food is one example of such a product. It is typically sold, for reasons of economy and convenience, in bulk quantities.
The containers used, however, are plastic-lined paper bags, wax-lined paper bags, or cardboard boxes, which containers do little to prevent the long term absorption or release of moisture or emission of odor during the period of time in which the products are being consumed. Once these containers are opened, product freshness deteriorates rapidly. At present, purchasers of such bulk-quantity products, in order to preserve freshness, are required to re-store the product in a plurality of smaller resealable containers immediately after the bulk-quantity container is opened. The bothersome procedure of pouring pet food from a large paper bag into a plurality of small resealable plastic containers is well-known to many pet owners.
Another problem with known bulk-quantity containers is their lack of structure for controlling the pouring of the product from the bag. Again, pet owners are all too familiar with the experience of pet food rolling around the kitchen floor when pet food is poured from a paper container into a plurality of smaller, resealable plastic containers. Therefore, it is desirable to provide a flexible bag for bulk quantity products in which the bag itself is resealable and the pouring of the product can be easily controlled.
A further problem with known bulk-quantity containers is their non-homogenous structure. For example, known pet food containers are generally dual substrate systems combining paper, wax paper and/or plastic. Disposal of such dual-substrate containers is quite difficult and injurious to the environment. Like-material containers would allow recycling of the material with the known environmental and economic advantageous thereof. Any bag for this use must, however, be relatively easy and economical to manufacture.
U.S. Pat. No. 4,573,203, issued to the present inventor, discloses a plastic bag having laminated plastic front and rear panels with a loop handle extending therebetween. A line of perforations extends across the top gusset of the bag to provide access of the interior thereof. While this bag is quite useful, it is not resealable and thus inapplicable to products which must retain their freshness.
U.S. Pat. No. 4,713,839, also issued to the present inventor, discloses in FIG. 1, a resealable flexible plastic bag with a loop handle in which a tongue-and-groove resealable structure is formed on the top gusset of the bag. However, as shown in FIG. 1 of that patent, the resealable closure is coupled to the bag ends in such a fashion that the resealable closure lies flat against the top gusset when the bag is filled with product. Also, the resealable closure is formed in the very middle of the top gusset with a line of perforations in the outer gusset beneath the resealable closure. This configuration of resealable closure may make pouring product from the bag inconvenient since the resealable closure tends to be difficult to handle once a given amount of product is emptied.
U.S. Pat. No. 4,877,336, also issued to the present inventor, discloses a duplex bag having a loop handle and a resealable closure in the top gusset, as shown in FIG. 13 thereof. However, this bag offers only a single sheet of plastic between the product and the resealable closure, thus proving somewhat disadvantageous in terms of ensuring product freshness.
The problems solved by the present invention relate to providing a flexible, single-material duplex bag for storing a pourable product while retaining its freshness.